| 年度 | 实际值 |
|---|---|
| 1992 | 19.6 |
| 1993 | |
| 1994 | |
| 1995 | 17.7 |
| 1996 | |
| 1997 | |
| 1998 | |
| 1999 | 17.56 |
| 2000 | 179963 |
| 2001 | 175472 |
| 2002 | 14.6409 |
| 2003 | 12.9082 |
| 2004 | 13.917 |
| 2005 | 13.6994 |
| 2006 | 13.79 |
| 2007 | 13.89 |
| 2008 | 13.32 |
| 2009 | 13.3331 |
| 2010 | 13.6468 |
| 2011 | 13.763 |
| 2012 | 13.86 |
| 2013 | 14.33 |
| 2014 | 14.73 |
| 2015 | 17.25 |
| 2016 | 17.46 |